Comparative response of onion (Allium cepa) to two sources of sulphur

An experiment was conducted during 2000-01 and 2001-02 at Palampur to compare the effects of 2 sources of sulphur (S-95 and gypsum) on onion (Allium cepa L.) crop under acidic soil and to work out their optimum doses independently. Fertilizer Testing Model was used to know the differences in the fertilizers at linear as well as curvature level. The other statistical tools like 't' test considers linearity and curvature independently. The results showed the Superiority of gypsum in response both at linear and curvature level by 0.0721 and 0.00066 tonne/ha. This implies that not only the limiting (maximum yield) was higher but the response / kg gypsum was also more. Multi fertilizer Response Model was used to work Out the optimum dose of fertilizers. The results indicated Optimum level of S-95 to be 42.14 kg/ha as against 55.17 for gypsum. The returns over fertilizer cost for S-95 and gypsum were worked out to be Rs 60 911 and 81 306 respectively. The study clearly indicates that gypsum is a superior S source for onion crop.